The present invention relates to a model applied in researching and building training method about learning and memory behavior of animals, especially relates to an animal memory training system with closed rotary maze. The present invention can be applied in the field of neurophysiology, neuropharmacology, psychology etc.
At present, animal behavior experiment is a significant and indispensable means to research higher brain function and other neurosciences problems. Especially, it plays a more important role in behavioral medicine researching aspect, such as neurophysiology, neuropharmacology etc. Maze experiment, a classical project of behavior experiment, is one of the most commonly used experiments for researching learning and memory function of rats (or mice), and is also a commonly used animal model of cognitive drug screening.
In a maze task, the instrument of the maze device can tell the animals that what they should do (like the instruction of the experiment done by human beings). In this task, the researchers always refer to these two concepts, working memory and reference memory. For accomplishing a task, animals require primarily the reference memory, which show that animals learn relevant information (such as the location of spatial clues, the structure of the maze, experiment rules etc.) between each trail of the task. Therefore, in the process of animals establishing reference memory, reference information should exist in the course of all trails. In laboratory circumstance, the working memory of animals is defined as the ability of persisting information in each trail of a experiment session. By comparison, working memory is always different in each trail, and is defined as the ability of animals to persist information (the place they have arrived) in each trail. After a trail, rats can erase the specific working memory of this trail, and keep the reference memory permanently. Therefore, the working memory only contribute to a trail, however, the reference memory is long-term memory.
Maze device in the prior art mainly includes the following types:
1. Dry maze model for measuring the working memory of animals. Dry mazes mainly refer to radial arm mazes, Y-mazes, T-mazes etc. Since reward and punishment is not provided in Y-mazes, T-mazes or Barnes mazes, and completely take advantage of the discovery instinct of animals, the animals is motivated by the hunger motivation to perform learning and memory in this type of maze task. So, the food intake of animals should be strictly controlled, thus their body weight should be decreased to 85% of original. However, the problem exist in this method is that the non-learning factor, such as the instinct of animals walking around the arm, the hunger lever, and so on, will influence on the experiment result.
2. Water maze model for measuring the working memory of animals. Morris Water Maze (MWM) is a classical water maze model, which performs learning and memory by taken advantage of the escaping motivation of seeking platform to prevent from drowning. In addition, on the bases of dry mazes, the experiment device is filled with water to form 8-arm radial water mazes, water T-mazes, or water Y-mazes, so as to eliminate the influence of smell clues on the experiment result. Employing water mazes to perform behavior test, it is not required to control the food and water intake of animals, and demands a short period, about one week, for training animals. It also enables to establish an image automatic acquisition and analysis system using computer, and enables to draw relevant histograms and running track diagrams, according to the collected data, so as to further analysis and discuss the experiment result by the researcher. Since the swimming latency of animals is correlated with their kinesiological condition, the shortcoming of MWM is that drugs affected animals' kinesiological condition, and animals' condition probably influence on the normal experiment result. Moreover, the experiment could be performed just in a few well equipped laboratories, because of the demand of monitoring system and analysis software. Lots of factors should be considered to design the experiment procedure, as well as experimenters is required to have certain knowledge of neurophysiology, cognitive physiology, and mathematical statistics, makes it difficult to perform experiment and to explain the result, and limits the wide application of this maze. Because of too much energy consumption, and too much body temperature loss, it is difficult for old and frail rats to accomplish task. Of course, not all mouse strains can be employed to perform Morris maze test. BALB/C mice are unable to learn how to perform this task (never make progress as learning days increasing). 129/SvJ mice show poor performance, and show tremendous difference between individuals. Some strains, like 129/SvJ mice strain, because of age-related visual pathway lesions, makes it difficult to accomplish learning and memory task based on visual sense, when they are old. Because of the presence of alopecia in C57BL/6 mice strain, some mice probably feel depressed, combined with ulcerative dermatitis, it affects the swimming abilities of mice and finally affects the experiment performance. This maze process is not sensitive to learning and memory ability slightly dropping off. Submerging animals into water maybe cause endocrine or other stress affects, the interaction between the later and cerebral lesions or pharmacological action exists uncertainty. The experiment need to be done by manual operation even via an automatic monitoring system, it makes the experiment to be boring. The experiment occupies too large testing area.
3. Other rats behavior model. One trial passive avoidance and step-down (or climbing pole) model are two simple models for researching learning and memory, and are suitable for researching memory retention and memory consolidation. These two models test the memory retention and memory consolidation via recording how long the animals never get into the small chamber with electric shock or never jump away from the platform, since suffered an electrical shock. New object recognition experiment is a model to test non-spatial working memory abilities of animals, which apply the principle that animals tend to discover new objects by nature. If the animals have remember pre-existing objects, the animals should expend less discovery time on the pre-existing objects the than the new objects, in test procedure.
In conclusion, aforesaid classical maze training systems have different extent of limitations, which includes various human factors, troublesome technical operation, and lack of comprehensive influence factors stimulated by electric, sound (noise), and light condition. In order to solve aforesaid problems, the inventor of the present invention has invented and published a solution in patent application CN200610045868.9, through long-term research. That is a mouse auditory and vision memory model and its intelligent behavior test system. The auditory and vision memory model comprises a maze with a data acquisition section, a destination section, and connecting channel thereof. A circular dark box type maze with multiple channels is used as the maze device, whose case with a lid and a barrier bottom, is divided into 3 sections by partitions. One of the sections is destination section, and the others are data acquisition sections. Some similar caves-like channels with adjustable one-way doorway are equipped at the bottom of the partitions, at equal distances. Two groups of infrared transmitting and receiving photoelectrical elements are provided at the side of the caves-like channel doorway. In each section, controlled lighting is provided. In each section of the barrier bottom, an electrical shock conductor controlled randomly, generating different gradient voltage strap. A hard light generating unit, a noise generating unit, and a video tracking unit are provided at the top of the central pillar in the case. Said auditory and vision memory model use controlled lightings cooperate with the habit of rat chasing darkness, propels rat to move voluntarily in the case. Combined with electric shock generated from the different gradient voltage strap of the conductor, the rat is controlled and propelled to passively move. Said system can be applied on fasted rats or non-fasted rats. Unlike the water maze training propel animals to swim, combined the voluntary movement of rats' natural moving mode, with the passive movement propelled by the gradient voltage, the rat is prevented from leaving the predetermined channel, and from staying for different time in every sections. The time data get more accurate. The animals' track in the maze is detected correctly, at real time, by the infrared transmitting and receiving photoelectrical elements equipped at side of the doorway. During using process, the inventor found out that said maze system has the disadvantages as following. The electric shock propelling the rat is not moderate enough. The propelling of gradient voltage is easy to hurt animal seriously or not. The device is complicate. Moreover, the device is not perfect, because animals may complete the experiment by smell. The stimulating system has defects of failure stimulating accurately and in time, with single type of stimulating. Electric stimulation and wounding stimulation cause side effect on animals. And operation is not inconvenient. Aforesaid defects effect the experiment result, and weaken the accuracy of the experiment data.
Generally speaking, the maze training system in the prior art needs to be improved, according to the actual demand of establishing a mode for animals learning and memory behavior training method.